从select中选择count(*)

Question

我试图从以下查询中获取行数.我只将行数计为1,但有35条记录.能告诉我如何从内部查询中获取计数吗？

谢谢

SELECT COUNT(*)(SELECT DISTINCT a.my_id, a.last_name, a.first_name, b.temp_val
                FROM Table_A a INNER JOIN Table_B b on a.a_id = b.a_id)

Answer 1

你错过了一个FROM,你需要给子查询一个别名.

SELECT COUNT(*) FROM 
(
  SELECT DISTINCT a.my_id, a.last_name, a.first_name, b.temp_val
   FROM dbo.Table_A AS a 
   INNER JOIN dbo.Table_B AS b 
   ON a.a_id = b.a_id
) AS subquery;